Heating device with hot water supply function

ABSTRACT

A heating device with hot water supply function includes: a combustion means; a first heat exchanger; a circulation passage that connects the first heat exchanger and an room heating unit; a circulation pump; a bypass passage that branches off from the circulation passage; a second heat exchanger for hot water supply provided in the bypass passage; a cold water supply passage; a hot water supply passage for supply of hot water from the second heat exchanger; and a distribution means that is provided at a branching section and whose distribution ratio can be adjusted, so that it becomes possible selectively to execute either only room heating operation, or only hot water supply operation, or simultaneous room heating operation and hot water supply operation; wherein the hot water supply outlet, the thermal medium inlet, and the room heating outlet of the distribution means are at the same height.

BACKGROUND OF THE INVENTION

The present invention relates to a heating device with hot water supply function that performs room heating by supplying heat produced by combustion to a thermal medium for room heating, and that also performs supply of hot water by supplying heat to cold water by heat exchange with the thermal medium for room heating; and in particular relates to a heating device with hot water supply function that is capable of performing room heating operation and hot water supply operation simultaneously.

In the prior art, heating devices with hot water supply function that are capable of performing changeover between room heating operation and hot water supply operation have been widely employed in practice. Such a heating device with hot water supply function typically comprises a combustion means, a heat exchanger, a circulation passage that connects between the heat exchanger and a room heating unit that is installed inside a building, a circulation pump provided in the circulation passage, a bypass passage that branches off from the circulation passage and bypasses the room heating unit, and so on. A changeover means that is capable of performing changeover so that the thermal medium for room heating flows either in the circulation passage or in the bypass passage is provided at the location where the bypass passage branches off from the circulation passage. And a heat exchanger for hot water supply is provided in the bypass passage, with a cold water supply passage that supplies fresh cold water and a hot water supply passage for supplying heated water to a hot water supply faucet or the like from the heat exchanger for hot water supply both being connected to the heat exchanger for hot water supply.

The thermal medium for room heating flows due to the operation of the circulation pump, and is heated in the heat exchanger by utilizing the combustion heat provided by the combustion means. During room heating operation the changeover means is changed over so that the thermal medium for room heating flows in the circulation passage, in order for the thermal medium for room heating to which heat has been supplied to be utilized by the room heating unit. The heated thermal medium for room heating then flows through the circulation passage with its heat being dissipated by the room heating unit, and returns to the heat exchanger.

On the other hand, during hot water supply operation, the changeover means is changed over so that the thermal medium for room heating flows in the bypass passage, in order for the thermal medium for room heating to which heat has been supplied to be utilized by the heat exchanger for hot water supply. The cold water that is supplied from the cold water supply passage is heated in the heat exchanger for hot water supply due to heat exchange with the thermal medium for room heating. And the thermal medium for room heating returns to the heat exchanger, after having exchanged heat with cold water in the heat exchanger for hot water supply. Moreover, the hot water that has been heated by the heat exchanger for hot water supply is then supplied to a hot water supply faucet or the like via the hot water supply passage from.

Such a heating device with hot water supply function that performs changeover between room heating operation and hot water supply operation in this manner has the problem of being somewhat inconvenient, due to the fact that room heating operation and hot water supply operation cannot both be performed simultaneously.

Due to these considerations, the present applicant has already proposed a heating device with hot water supply function with which simultaneous room heating and hot water supply operation are possible, and that performs both room heating operation and hot water supply operation simultaneously by adjusting the distribution ratio of a distribution means for the thermal medium (refer to Japanese Patent Application No.2016 -146594). In simultaneous room heating and hot water supply operation, the circulating thermal medium for room heating is distributed between the room heating unit and the heat exchanger for hot water supply, so that hot water is supplied by heat being supplied to cold water in the heat exchanger for hot water supply.

Typically, a plate type heat exchanger is employed as the heat exchanger for hot water supply. Since multiple passages whose cross-sectional areas are small are provided in the interior of a plate type heat exchanger, accordingly in some cases the flow of the thermal medium for room heating and/or the flow of hot water for hot water supply may be difficult. Due to this, a structure is per se known in which a passage whose resistance to water flow is low is provided within the plate type heat exchanger, as for example in the case of the plate type heat exchanger of Japanese Patent No. 5,882,491. Because the water flow resistance is low, both the thermal medium for room heating and the hot water for hot water supply can easily flow within this plate type heat exchanger.

However, since such a heating device with hot water supply function that is capable of performing room heating operation and hot water supply operation simultaneously needs to be equipped with a distribution valve to serve as a distribution means that is larger in size than a three-way valve that serves as a changeover means, accordingly it is not easy to house such a distribution valve in the relatively limited space within the heating device with hot water supply function. Additionally, such a heating device with hot water supply function is required to have both satisfactory hot water output characteristics during the supply of hot water and also satisfactory performance for drainage during maintenance. With the structure of Japanese Patent No. 5,882,491, although the flows of the thermal medium for room heating and of the hot water for hot water supply are improved to be satisfactory, the quality of the characteristics for hot water output including the characteristics of the passages connected to the plate type heat exchanger and the quality of the drainage performance are unclear.

An object of the present invention is to provide a heating device with hot water supply function, that is capable of performing any one of only room heating operation, or only hot water supply operation, or simultaneous room heating operation and hot water supply operation; and that, along with being provided with a distribution valve having satisfactory drainage performance, moreover is capable of implementing a satisfactory hot water output characteristic.

SUMMARY OF THE INVENTION

The present invention presents a heating device with hot water supply function, comprising: a combustion means; a heat exchanger for heating a thermal medium for room heating; a circulation passage that connects the heat exchanger and a room heating unit; a circulation pump for circulating the thermal medium provided in the circulation passage; a bypass passage that branches off from the circulation passage and bypasses the room heating unit; a heat exchanger for hot water supply provided in the bypass passage; a cold water supply passage for supplying cold water to the heat exchanger for hot water supply; a hot water supply passage for supply of hot water that has been heated by the heat exchanger for hot water supply at a predetermined set hot water supply temperature; and a distribution means that is provided at a branching section where the bypass passage branches off from the circulation passage, and whose distribution ratio can be adjusted, so that it becomes possible selectively to execute either only room heating operation, or only hot water supply operation, or simultaneous room heating operation and hot water supply operation; the distribution means being a distribution valve comprising a cylindrical main body portion and a hot water supply outlet and a thermal medium inlet and a room heating outlet that are formed on the main body portion, and is disposed so that an axial direction of the main body portion is horizontal and the hot water supply outlet, the thermal medium inlet, and the room heating outlet are all at the same height.

According to the present invention, the hot water supply outlet, the thermal medium inlet, and the room heating outlet of the distribution valve are all at the same height. Due to this, it is possible to obtain satisfactory drainage performance when the thermal medium is drained during maintenance or the like, since it is difficult for the thermal medium to stagnate within the distribution valve. Moreover, since the hot water supply outlet and the thermal medium inlet are at the same height, accordingly, when room heating operation has been stopped and the circulation of the thermal medium has ceased, even if the closing function of the distribution valve is insufficient, still no flow of the thermal medium within the distribution valve will occur from the thermal medium inlet toward the hot water supply outlet due to the propulsive force of natural convection, and the thermal medium for room heating will not flow into the heat exchanger for hot water supply. Accordingly, it is possible to prevent unanticipated supply of heat to the hot water in the heat exchanger, so that it is possible to obtain a satisfactory hot water output characteristic during supply of hot water.

In a preferable first aspect of the present, the hot water supply outlet, the thermal medium inlet, and the room heating outlet are disposed at different positions along the axial direction of the main body portion, with pointing toward different directions.

In a preferable second aspect of the present invention, the heat exchanger for hot water supply is a plate type heat exchanger that is formed as a rectangular parallelepiped, and the distribution means is disposed so that the axial direction of the main body portion is parallel to the longitudinal direction of the heat exchanger for hot water supply.

According to the second aspect, it is possible simply and easily to arrange the heat exchanger for hot water supply and the distribution valve in the limited space within the heating device with hot water supply function.

In a preferable third aspect of the present invention, the hot water supply outlet of the distribution means is directly connected to a thermal medium inlet port of the heat exchanger for hot water supply by use of a metallic connection clip.

According to the third aspect, the distribution valve and the heat exchanger for hot water supply are connected together through the shortest possible distance. Accordingly, it is possible to obtain a satisfactory output hot water characteristic during supply of hot water, since the thermal medium that is distributed by the distribution valve during the supply of hot water can flow immediately into the heat exchanger for hot water supply.

In a preferable fourth aspect of the present invention, the hot water supply outlet of the distribution means and the thermal medium inlet port of the heat exchanger for hot water supply are connected together via a straight pipe section, of which one end portion is connected to the thermal medium inlet port by a first quick fastener, and the other end portion is connected to the hot water supply outlet by a second quick fastener; and a distance between the hot water supply outlet of the distribution means and the thermal medium inlet port corresponds to a distance between a center of the first quick fastener in its width direction and a center of the second quick fastener in its width direction.

According to the fourth aspect, the distribution valve and the heat exchanger for hot water supply are connected together via the straight pipe section through the shortest possible distance. Accordingly, it is possible to obtain a satisfactory output hot water characteristic during supply of hot water, since the thermal medium that is distributed by the distribution valve during the supply of hot water can flow immediately into the heat exchanger for hot water supply.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing showing a heating device with hot water supply function according to an embodiment of the present invention;

FIG. 2 is an exploded perspective view of a portion for connection between a distribution valve and a heat exchanger for hot water supply;

FIG. 3 is a plan view showing a state in which the distribution valve and the heat exchanger for hot water supply are connected together;

FIG. 4 is a figure corresponding to FIG. 2, relating to a variant embodiment; and

FIG. 5 is a figure corresponding to FIG. 3, relating to the variant embodiment.

DETAILED DESCRIPTION

A heating device with hot water supply function according to an embodiment of the present invention will now be explained on the basis of the drawings. First, the overall structure of the heating device with hot water supply function 1 will be explained on the basis of FIG. 1.

The heating device with hot water supply function 1 circulates a thermal medium for room heating that has been heated by utilizing heat generated by a combustion section 2 to a room heating unit (not shown) that is installed in a room of a building, thereby performing room heating, and is also adapted to provide hot water supply by heating cold water by utilizing the heat of the room heating thermal medium while adjusting its temperature to a predetermined set hot water supply temperature. In FIG. 1, the arrow F represents supply of fuel, the arrow AS represents supply of air, the arrow E represents exhaust gas, the arrow D represents drainage, the arrow CW represents supply of cold water, the arrow HW represents supply of hot water, the arrow HS represents supply of the room heating thermal medium, the arrow HR represents return of the room heating thermal medium, and the arrow R represents replenishment of the room heating thermal medium.

The heating device with hot water supply function 1 comprises a combustion section 2 that constitutes a combustion means, a heat exchanger 10, a circulation passage 4 connecting the heat exchanger 10 and the room heating unit (not shown) that is provided inside a building, a circulation pump 11 that is provided in the circulation passage 4 on the upstream side of the heat exchanger 10, and so on. The combustion section 2 mixes fuel gas and air, and combusts the mixture. And the heat exchanger 10 supplies heat to the room heating thermal medium by exchanging heat between the combustion gas generated by the combustion section 2 and the room heating thermal medium.

Moreover, the heating device with hot water supply function 1 comprises a bypass passage 12 (a first bypass passage), a heat exchanger for hot water supply 20 that is provided in the first bypass passage 12, a cold water supply passage 19, a hot water supply passage 21, and so on. The first bypass passage 12 branches off from the circulation passage 4 on the downstream side of the heat exchanger 10 and bypasses the room heating unit, and joins to the circulation passage 4 on the upstream side of the circulation pump 11. And the cold water supply passage 19 supplies cold water to the heat exchanger for hot water supply 20. Moreover, the hot water supply passage 21 provides supply to a hot water supply faucet of hot water that has been heated up by application of heat by the heat exchanger 20.

Furthermore, the heating device with hot water supply function 1 comprises a control unit 7; and the various devices and so on described above, including the control unit 7, are contained within a casing 8. The control unit 7 receives detection signals from temperature sensors and so on that will be described hereinafter, and also performs control to operate the circulation pump 11 and a first distribution valve 30, so as to make it possible selectively to execute either only room heating operation, or only hot water supply operation, or simultaneous room heating operation and hot water supply operation.

Next, the circulation passage 4 will be explained.

The circulation passage 4 comprises a first temperature sensor 13 provided between the circulation pump 11 and the heat exchanger 10, and a second temperature sensor 14 provided at the downstream side of the heat exchanger 10. The first temperature sensor 13 detects the temperature of the room heating thermal medium flowing into the heat exchanger 10. And the second temperature sensor 14 detects the temperature of the room heating thermal medium to which heat has been supplied by the heat exchanger 10.

The first distribution valve 30, which is a distribution means, is provided at the branching section where the circulation passage 4 and the first bypass passage 12 branch apart. The first distribution valve 30 distributes the room heating thermal medium, to which heat has been supplied by the heat exchanger 10, to the circulation passage 4 and the first bypass passage 12, and is capable of adjusting its distribution ratio.

A pressure relief valve 16 for venting the pressure within the circulation passage 4 is provided between the heat exchanger 10 and the first distribution valve 30. And a room heating return temperature sensor 17 is provided on the upstream side of the circulation pump 11 and detects the temperature of the thermal medium returning from the room heating unit. A replenishment passage 18 for replenishment of the thermal medium is connected between the circulation pump 11 and the room heating return temperature sensor 17.

Next, the heat exchanger for hot water supply 20 will be explained. The heat exchanger 20 that is provided in the first bypass passage 12 is a plate type heat exchanger that is formed in the shape of a rectangular parallelepiped. In this plate type heat exchanger, a plurality of heat exchange plates are laminated together so that passages are defined between these heat exchange plates. Within the heat exchanger 20, mutually opposing flows for the thermal medium and for cold water supplied from the cold water supply passage 19 are defined between alternate ones of the heat exchange plates, so that these flows can exchange heat without mutually mixing together. These heat exchange plates are formed with roughnesses, in order to increase their surface areas and to enhance the heat exchange efficiency.

As shown in FIGS. 1 and 2, a connection portion 29 a is formed at a heating medium inlet port 29 for introducing the thermal medium to the heat exchanger 20. The connection portion 29 a includes a cylindrical passage portion 29 b that projects from the heat exchanger 20, an enlarged diameter portion 29 c at the end of the passage portion 29 b whose diameter is enlarged to be greater than that of the passage portion 29 b, and a flange portion 29 d that is formed at the end of the enlarged diameter portion 29 c. Similar connection portions are also formed at the thermal medium outlet, at the hot water inlet, and at the hot water outlet of the heat exchanger 20, and project in the same direction as its connection portion 29 a. The heat exchanger 20 is fixed in the casing 8 by its surface on which these connection portions 29 a and so on are not formed, in an attitude in which its longitudinal direction is horizontal.

Next, the cold water supply passage 19 and the hot water supply passage 21 will be explained.

As shown in FIG. 1, the cold water supply passage 19 comprises a second distribution valve 23, a flow rate adjustment valve 24, a hot water supply flow rate sensor 25, and an intake cold water temperature sensor 26. The second distribution valve 23 distributes cold water to the cold water supply passage 19 and to a hot water supply bypass passage 22 (a second bypass passage 22) that is branched off from the cold water supply passage 19 at the second distribution valve 23, and its distribution ratio can be adjusted. Accordingly, the second distribution valve 23 serves as a flow rate adjustment means that adjusts the flow rate of cold water flowing in the second bypass passage 22. And the flow rate adjustment valve 24 adjusts the flow rate of the cold water entering into the second distribution valve 23. The hot water supply flow rate sensor 25 detects the adjusted flow rate of cold water. Moreover, the intake cold water temperature sensor 26 detects the temperature of the cold water entering the second distribution valve 23.

The second bypass passage 22 joins to the hot water supply passage 21 on the downstream side of the heat exchanger 20. An output hot water temperature sensor 27, which is a temperature detection means, is provided in the hot water supply passage 21 between the junction of the hot water supply passage 21 and the second bypass passage 22, and the heat exchanger 20. This output hot water temperature sensor 27 detects the temperature of the hot water outputted from the heat exchanger 20.

A hot water supply temperature sensor 28 is provided at the downstream end of the hot water supply passage 21. This hot water supply temperature sensor 28 detects the temperature of the hot water that has been obtained by mixing together the hot water to which heat has been supplied by the heat exchanger for hot water supply 20 and cold water flowing through the second bypass passage 22.

Next, the first distribution valve 30 will be explained.

As shown in FIGS. 2 and 3, the first distribution valve 30 comprises a cylindrical main body portion 31 and an driving adjustment portion 32 at one end portion in the axial direction of the main body portion 31 for adjusting the distribution ratio provided by the first distribution valve 30. A hot water supply outlet 33, a thermal medium inlet 34, and a room heating outlet 35 are arranged on the main body portion 31, at different positions along its axial direction and pointing in different directions.

The hot water supply outlet 33 is arranged at a side portion of the main body portion 31 that is close to the driving adjustment portion 32 of the main body portion 31, so as to point outward along a radial direction thereof. The room heating outlet 35 is arranged at the other end portion of the main body portion 31 in its axial direction opposite to the driving adjustment portion 32, so as to point in the direction away from the driving adjustment portion 32. And the thermal medium inlet 34 is arranged at a position in the axial direction of the main body portion 31 between the hot water supply outlet 33 and the room heating outlet 35, so as to point in the direction opposite to the direction in which the hot water supply outlet 33 is pointing.

The first distribution valve 30 is arranged with the axial direction of its main body portion 31 (i.e. its longitudinal direction) horizontal and parallel to the longitudinal direction of the heat exchanger 20 which is formed as a rectangular parallelepiped, and its hot water supply outlet 33 is arranged so as to point toward the heat exchanger 20. At this time, the hot water supply outlet 33, the thermal medium inlet 34, and the room heating outlet 35 are at the same height. The hot water supply outlet 33 is directly connected to the connection portion 29 a of the thermal medium inlet port 29 of the heat exchanger 20 by the use of a metallic connection clip.

The hot water supply outlet 33 includes a cylindrical passage portion 33 a and an enlarged diameter portion 33 b at the end of the passage portion 33 a whose external diameter is enlarged to be greater than that of the passage portion 33 a. This enlarged diameter portion 33 b is fitted to the enlarged diameter portion 29 c of the connection portion 29 a and is fixed thereto by the abovementioned metallic connection clip. For example, a quick fastener 36 may be used as this metallic connection clip. A sealing member is provided around the circumference of the enlarged diameter portion 33 b, so as to ensure that the hot water supply outlet 33 is connected to the connection portion 29 a of the thermal medium inlet port 29 in a water-tight manner.

Next, the operation and the beneficial effects of this heating device with hot water supply function 1 will be explained.

Since, along with the axial direction of the main body portion 31 of the first distribution valve 30 being oriented horizontally and parallel to the longitudinal direction of the heat exchanger 20 which is shaped as a rectangular parallelepiped, also the hot water supply outlet 33 is disposed to point toward the heat exchanger 20, therefore the hot water supply outlet 33, the thermal medium inlet 34, and the room heating outlet 35 are all at the same height. And, since the first distribution valve 30 is thus disposed so that the thermal medium flows horizontally in its interior, accordingly, when the thermal medium is drained for maintenance or the like, the thermal medium does not stagnate within the first distribution valve 30, so that satisfactory drainage performance can be obtained.

Moreover, since the thermal medium inlet 34 and the hot water supply outlet 33 are at the same height, accordingly, when the room heating operation has been stopped and circulation of the thermal medium has ceased, flow of the thermal medium within the first distribution valve 30 from the thermal medium inlet 34 toward the hot water supply outlet 33 due to natural convection acting as a propulsive force does not take place. Because of this, even if the closing function of the first distribution valve 30 is insufficient, still the thermal medium will not flow into the heat exchanger 20. Accordingly, it is possible to prevent unanticipated supply of heat to the hot water in the heat exchanger 20, so that it is possible to obtain a satisfactory hot water output characteristic during supply of hot water.

Furthermore, since the first distribution valve 30 is directly connected to the heat exchanger 20, accordingly it is possible for the thermal medium that has been distributed by the first distribution valve 30 to be immediately flowed into the heat exchanger 20, so that it is possible to obtain a satisfactory output hot water characteristic during hot water supply.

Yet further, the first distribution valve 30 is disposed so that the axial direction of its main body portion 31, which is its longitudinal direction, is parallel to the longitudinal direction of the heat exchanger 20, and moreover so that the distance between the heat exchanger 20 and the first distribution valve 30 is short. Accordingly, it is possible easily to arrange the first distribution valve 30 and the heat exchanger 20 in the limited space inside the heating device with hot water supply function 1.

Next, a variant embodiment in which the connection construction that connects between the first distribution valve 30 and the heat exchanger 20 is modified will be explained on the basis of FIGS. 4 and 5.

A first distribution valve 40 comprises a cylindrical main body portion 41 and an driving adjustment portion 42 at one end portion in the axial direction of the main body portion 41 for adjusting its distribution ratio. A hot water supply outlet 43, a thermal medium inlet 44, and a room heating outlet 45 are disposed on the main body portion 41, at different positions along its axial direction and pointing in different directions.

The hot water supply outlet 43 is arranged at a side portion of the main body portion 41 that is close to the driving adjustment portion 42 of the main body portion 41, so as to point outward along a radial direction thereof. The room heating outlet 45 is arranged at the other end portion of the main body portion 41 in its axial direction opposite to the driving adjustment portion 42, so as to point in the direction away from the driving adjustment portion 42. And the thermal medium inlet 44 is arranged at a position in the axial direction of the main body portion 41 between the hot water supply outlet 43 and the room heating outlet 45, so as to point in the direction opposite to the direction in which the hot water supply outlet 43 is pointing.

The first distribution valve 40 is arranged with the axial direction of its main body portion 41 (i.e. its longitudinal direction) horizontal and parallel to the longitudinal direction of the heat exchanger 20 which is formed as a rectangular parallelepiped, and its hot water supply outlet 43 is arranged so as to point toward the heat exchanger 20. At this time, the hot water supply outlet 43, the thermal medium inlet 44, and the room heating outlet 45 are at the same height.

As shown in FIGS. 1, 4, and 5, the hot water supply outlet 43 of the first distribution valve 40 is connected to the connection portion 29 a of the thermal medium inlet port 29 of the heat exchanger 20 via a straight pipe section 37. The hot water supply outlet 43 of the first distribution valve 40 has a cylindrical passage portion 43 a, an enlarged diameter portion 43 b at the end of the passage portion 43 a whose external diameter is enlarged to be greater than that of the passage portion 43 a, and a flange portion 43 c that is formed on the end portion of the enlarged diameter portion 43 b.

The two ends of the straight pipe section 37 are provided with enlarged diameter portions 38, 39 whose external diameters are enlarged. The enlarged diameter portion 38 is fitted to the enlarged diameter portion 29 c of the thermal medium inlet port 29 and is fixed thereto by a first quick fastener 46, so that it cannot come off. And the enlarged diameter portion 39 is fitted to the enlarged diameter portion 43 b of the hot water supply outlet 43 and is fixed thereto by a second quick fastener 47, so that it cannot come off. At this time, since the first and second quick fasteners 46, 47 are closely approached together so as to contact one another, accordingly the first distribution valve 40 and the heat exchanger for hot water supply 20 are connected together via the straight pipe section 37 through as short a distance as possible. Sealing members are provided around the circumferences of the enlarged diameter portions 38, 39, in order to ensure water-tight connections.

Engagement portions are provided on the first and second quick fasteners 46, 47 at their central portions in their width directions which are parallel to the axial direction of the straight pipe section 37, for engaging with the flange portion 29 d of the thermal medium inlet port 29, the flange portion 43 c of the hot water supply outlet 43, and the enlarged diameter portions 38, 39 of the straight pipe section 37. Accordingly, the distance between the hot water supply outlet 43 and the thermal medium inlet port 29 corresponds to the distance between the center in the width direction of the first quick fastener 46 and the center in the width direction of the second quick fastener 47. It should be understood that, if the first and second quick fasteners 46, 47 are of the same size, then this distance will correspond to the width of the first quick fastener 46 or to the width of the second quick fastener 47.

Next, the operation and the beneficial effects of the connection construction shown in FIGS. 4 and 5 will be explained. Since, along with the axial direction of the main body portion 41 of the first distribution valve 40 being oriented horizontally and parallel to the longitudinal direction of the heat exchanger 20 which is shaped as a rectangular parallelepiped, also the hot water supply outlet 43 is disposed to point toward the heat exchanger 20, therefore the hot water supply outlet 43, the thermal medium inlet 44, and the room heating outlet 45 are all at the same height. And, since the first distribution valve 40 is thus disposed so that the thermal medium flows horizontally in its interior, accordingly, when the thermal medium is drained for maintenance or the like, the thermal medium does not stagnate within the first distribution valve 40, so that satisfactory drainage performance can be obtained.

Moreover, since the thermal medium inlet 44 and the hot water supply outlet 43 are at the same height, accordingly, when the operation has been stopped and circulation of the thermal medium has ceased, flow of the thermal medium within the first distribution valve 40 from the thermal medium inlet 44 toward the hot water supply outlet 43 due to natural convection acting as a propulsive force does not take place. Because of this, even if the closing function of the first distribution valve 40 is insufficient, still the thermal medium will not flow into the heat exchanger 20. Accordingly, it is possible to prevent unanticipated supply of heat to the hot water in the heat exchanger 20, so that it is possible to obtain a satisfactory hot water output characteristic during supply of hot water.

Furthermore, the first distribution valve 40 is connected to the heat exchanger 20 via the straight pipe section 37 which is held on by the first and second quick fasteners 46, 47, and the distance between the center of the first quick fastener 46 in its width direction and the center of the second quick fastener 47 in its width direction is made to be as short as possible. Accordingly it is possible for the thermal medium that has been distributed by the first distribution valve 40 to be immediately flowed into the heat exchanger 20, so that it is possible to obtain a satisfactory output hot water characteristic during hot water supply.

Yet further, the first distribution valve 40 is disposed so that the axial direction of its main body portion 41, which is its longitudinal direction, is parallel to the longitudinal direction of the heat exchanger 20, and moreover so that the distance between the heat exchanger 20 and the first distribution valve 40 is short. Accordingly, it is possible easily to arrange the first distribution valve 40 and the heat exchanger 20 for hot water supply in the limited space inside the heating device with hot water supply function 1A.

Apart from the above, for a person skilled in the art, without deviating from the gist of the present invention, it would be possible to implement the present invention by making additions of various types to the embodiment described above; and the present invention is to be considered as encompassing modifications of this kind. 

1. A heating device with hot water supply function, comprising: a combustion means; a heat exchanger for heating a thermal medium for room heating; a circulation passage that connects the heat exchanger and a room heating unit; a circulation pump for circulating the thermal medium provided in the circulation passage; a bypass passage that branches off from the circulation passage and bypasses the room heating unit; a heat exchanger for hot water supply provided in the bypass passage; a cold water supply passage for supplying cold water to the heat exchanger for hot water supply; a hot water supply passage for supply of hot water that has been heated by the heat exchanger for hot water supply at a predetermined set hot water supply temperature; and a distribution means that is provided at a branching section where the bypass passage branches off from the circulation passage, and whose distribution ratio can be adjusted, so that it becomes possible selectively to execute either only room heating operation, or only hot water supply operation, or simultaneous room heating operation and hot water supply operation; the distribution means being a distribution valve comprising a cylindrical main body portion, and a hot water supply outlet and a thermal medium inlet and a room heating outlet that are formed on the main body portion, and is disposed so that the axial direction of said main body portion is horizontal and the hot water supply outlet, the thermal medium inlet, and the room heating outlet are all at the same height.
 2. The heating device with hot water supply function according to claim 1, wherein the hot water supply outlet, the thermal medium inlet, and the room heating outlet are disposed at different positions along the axial direction of the main body portion, with pointing toward different directions.
 3. The heating device with hot water supply function according to claim 1, wherein the heat exchanger for hot water supply is a plate type heat exchanger that is formed as a rectangular parallelepiped; and the distribution means is disposed so that the axial direction of the main body portion is parallel to a longitudinal direction of the heat exchanger for hot water supply.
 4. The heating device with hot water supply function according to claim 3, wherein the hot water supply outlet of the distribution means is directly connected to a thermal medium inlet port of the heat exchanger for hot water supply by use of a metallic connection clip.
 5. The heating device with hot water supply function according to claim 3, wherein the hot water supply outlet of the distribution means and the thermal medium inlet port of the heat exchanger for hot water supply are connected together via a straight pipe section, of which one end portion is connected to the thermal medium inlet port by a first quick fastener, and the other end portion is connected to the hot water supply outlet by a second quick fastener; and a distance between the hot water supply outlet of said distribution means and the thermal medium inlet port corresponds to a distance between the center of the first quick fastener in its width direction and a center of the second quick fastener in its width direction. 